features.h 14 KB

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  1. /* Copyright (C) 1991-1993,1995-2006,2007,2009 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, see
  13. <http://www.gnu.org/licenses/>. */
  14. #ifndef _FEATURES_H
  15. #define _FEATURES_H 1
  16. /* These are defined by the user (or the compiler)
  17. to specify the desired environment:
  18. __STRICT_ANSI__ ISO Standard C.
  19. _ISOC99_SOURCE Extensions to ISO C89 from ISO C99.
  20. _POSIX_SOURCE IEEE Std 1003.1.
  21. _POSIX_C_SOURCE If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2;
  22. if >=199309L, add IEEE Std 1003.1b-1993;
  23. if >=199506L, add IEEE Std 1003.1c-1995;
  24. if >=200112L, all of IEEE 1003.1-2004
  25. if >=200809L, all of IEEE 1003.1-2008
  26. _XOPEN_SOURCE Includes POSIX and XPG things. Set to 500 if
  27. Single Unix conformance is wanted, to 600 for the
  28. sixth revision, to 700 for the seventh revision.
  29. _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
  30. _LARGEFILE_SOURCE Some more functions for correct standard I/O.
  31. _LARGEFILE64_SOURCE Additional functionality from LFS for large files.
  32. _FILE_OFFSET_BITS=N Select default filesystem interface.
  33. _BSD_SOURCE ISO C, POSIX, and 4.3BSD things.
  34. _SVID_SOURCE ISO C, POSIX, and SVID things.
  35. _ATFILE_SOURCE Additional *at interfaces.
  36. _GNU_SOURCE All of the above, plus GNU extensions.
  37. _REENTRANT Select additionally reentrant object.
  38. _THREAD_SAFE Same as _REENTRANT, often used by other systems.
  39. _FORTIFY_SOURCE If set to numeric value > 0 additional security
  40. measures are defined, according to level.
  41. The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
  42. If none of these are defined, the default is to have _SVID_SOURCE,
  43. _BSD_SOURCE, and _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
  44. 200112L. If more than one of these are defined, they accumulate.
  45. For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
  46. together give you ISO C, 1003.1, and 1003.2, but nothing else.
  47. These are defined by this file and are used by the
  48. header files to decide what to declare or define:
  49. __USE_ISOC11 Define ISO C11 things.
  50. __USE_ISOC99 Define ISO C99 things.
  51. __USE_ISOC95 Define ISO C90 AMD1 (C95) things.
  52. __USE_POSIX Define IEEE Std 1003.1 things.
  53. __USE_POSIX2 Define IEEE Std 1003.2 things.
  54. __USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
  55. __USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things.
  56. __USE_XOPEN Define XPG things.
  57. __USE_XOPEN_EXTENDED Define X/Open Unix things.
  58. __USE_UNIX98 Define Single Unix V2 things.
  59. __USE_XOPEN2K Define XPG6 things.
  60. __USE_XOPEN2K8 Define XPG7 things.
  61. __USE_LARGEFILE Define correct standard I/O things.
  62. __USE_LARGEFILE64 Define LFS things with separate names.
  63. __USE_FILE_OFFSET64 Define 64bit interface as default.
  64. __USE_BSD Define 4.3BSD things.
  65. __USE_SVID Define SVID things.
  66. __USE_MISC Define things common to BSD and System V Unix.
  67. __USE_ATFILE Define *at interfaces and AT_* constants for them.
  68. __USE_GNU Define GNU extensions.
  69. __USE_REENTRANT Define reentrant/thread-safe *_r functions.
  70. __USE_FORTIFY_LEVEL Additional security measures used, according to level.
  71. __FAVOR_BSD Favor 4.3BSD things in cases of conflict.
  72. The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
  73. defined by this file unconditionally. `__GNU_LIBRARY__' is provided
  74. only for compatibility. All new code should use the other symbols
  75. to test for features.
  76. All macros listed above as possibly being defined by this file are
  77. explicitly undefined if they are not explicitly defined.
  78. Feature-test macros that are not defined by the user or compiler
  79. but are implied by the other feature-test macros defined (or by the
  80. lack of any definitions) are defined by the file. */
  81. /* Undefine everything, so we get a clean slate. */
  82. #undef __USE_ISOC11
  83. #undef __USE_ISOC99
  84. #undef __USE_ISOC95
  85. #undef __USE_POSIX
  86. #undef __USE_POSIX2
  87. #undef __USE_POSIX199309
  88. #undef __USE_POSIX199506
  89. #undef __USE_XOPEN
  90. #undef __USE_XOPEN_EXTENDED
  91. #undef __USE_UNIX98
  92. #undef __USE_XOPEN2K
  93. #undef __USE_XOPEN2K8
  94. #undef __USE_LARGEFILE
  95. #undef __USE_LARGEFILE64
  96. #undef __USE_FILE_OFFSET64
  97. #undef __USE_BSD
  98. #undef __USE_SVID
  99. #undef __USE_MISC
  100. #undef __USE_ATFILE
  101. #undef __USE_GNU
  102. #undef __USE_REENTRANT
  103. #undef __USE_FORTIFY_LEVEL
  104. #undef __FAVOR_BSD
  105. #undef __KERNEL_STRICT_NAMES
  106. /* Suppress kernel-name space pollution unless user expressedly asks
  107. for it. */
  108. #ifndef _LOOSE_KERNEL_NAMES
  109. # define __KERNEL_STRICT_NAMES
  110. #endif
  111. /* Always use ISO C things. */
  112. #define __USE_ANSI 1
  113. /* Convenience macros to test the versions of glibc and gcc.
  114. Use them like this:
  115. #if __GNUC_PREREQ (2,8)
  116. ... code requiring gcc 2.8 or later ...
  117. #endif
  118. Note - they won't work for gcc1 or glibc1, since the _MINOR macros
  119. were not defined then. */
  120. #if defined __GNUC__ && defined __GNUC_MINOR__
  121. # define __GNUC_PREREQ(maj, min) \
  122. ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  123. #else
  124. # define __GNUC_PREREQ(maj, min) 0
  125. #endif
  126. /* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
  127. #if defined _BSD_SOURCE && \
  128. !(defined _POSIX_SOURCE || defined _POSIX_C_SOURCE || \
  129. defined _XOPEN_SOURCE || defined _XOPEN_SOURCE_EXTENDED || \
  130. defined _GNU_SOURCE || defined _SVID_SOURCE)
  131. # define __FAVOR_BSD 1
  132. #endif
  133. /* If _GNU_SOURCE was defined by the user, turn on all the other features. */
  134. #ifdef _GNU_SOURCE
  135. # undef _ISOC99_SOURCE
  136. # define _ISOC99_SOURCE 1
  137. # undef _ISOC11_SOURCE
  138. # define _ISOC11_SOURCE 1
  139. # undef _POSIX_SOURCE
  140. # define _POSIX_SOURCE 1
  141. # undef _POSIX_C_SOURCE
  142. # define _POSIX_C_SOURCE 200809L
  143. # undef _XOPEN_SOURCE
  144. # define _XOPEN_SOURCE 700
  145. # undef _XOPEN_SOURCE_EXTENDED
  146. # define _XOPEN_SOURCE_EXTENDED 1
  147. # undef _LARGEFILE64_SOURCE
  148. # define _LARGEFILE64_SOURCE 1
  149. # undef _BSD_SOURCE
  150. # define _BSD_SOURCE 1
  151. # undef _SVID_SOURCE
  152. # define _SVID_SOURCE 1
  153. # undef _ATFILE_SOURCE
  154. # define _ATFILE_SOURCE 1
  155. #endif
  156. /* This macro indicates that the installed library is uClibc. Use
  157. * __UCLIBC_MAJOR__ and __UCLIBC_MINOR__ to test for the features in
  158. * specific releases. */
  159. #define __UCLIBC__ 1
  160. #ifdef __UCLIBC__
  161. /* Load up the current set of uClibc supported features along
  162. * with the current uClibc major and minor version numbers.
  163. * For uClibc release 0.9.26, these numbers would be:
  164. * #define __UCLIBC_MAJOR__ 0
  165. * #define __UCLIBC_MINOR__ 9
  166. * #define __UCLIBC_SUBLEVEL__ 26
  167. */
  168. # define __need_uClibc_config_h
  169. # include <bits/uClibc_config.h>
  170. # undef __need_uClibc_config_h
  171. /* For uClibc, always optimize for size -- this should disable
  172. * a lot of expensive inlining...
  173. * TODO: this is wrong! __OPTIMIZE_SIZE__ is an indicator of
  174. * gcc -Os compile. We should not mess with compiler inlines.
  175. * We should instead disable __USE_EXTERN_INLINES unconditionally,
  176. * or maybe actually audit and test uclibc to work correctly
  177. * with __USE_EXTERN_INLINES on.
  178. */
  179. # define __OPTIMIZE_SIZE__ 1
  180. /* disable unsupported features */
  181. # undef __LDBL_COMPAT
  182. # ifndef __UCLIBC_HAS_FORTIFY__
  183. # undef _FORTIFY_SOURCE
  184. # endif
  185. # ifndef __UCLIBC_HAS_THREADS__
  186. # if defined _REENTRANT || defined _THREAD_SAFE
  187. # warning requested reentrant code, but thread support was disabled
  188. # undef _REENTRANT
  189. # undef _THREAD_SAFE
  190. # endif
  191. # endif
  192. #endif /* __UCLIBC__ */
  193. /* If nothing (other than _GNU_SOURCE) is defined,
  194. define _BSD_SOURCE and _SVID_SOURCE. */
  195. #if (!defined __STRICT_ANSI__ && !defined _ISOC99_SOURCE && \
  196. !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE && \
  197. !defined _XOPEN_SOURCE && !defined _XOPEN_SOURCE_EXTENDED && \
  198. !defined _BSD_SOURCE && !defined _SVID_SOURCE)
  199. # define _BSD_SOURCE 1
  200. # define _SVID_SOURCE 1
  201. #endif
  202. /* This is to enable the ISO C11 extension. */
  203. #if (defined _ISOC11_SOURCE \
  204. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
  205. # define __USE_ISOC11 1
  206. #endif
  207. /* This is to enable the ISO C99 extension. */
  208. #if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \
  209. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
  210. # define __USE_ISOC99 1
  211. #endif
  212. /* This is to enable the ISO C90 Amendment 1:1995 extension. */
  213. #if (defined _ISOC99_SOURCE || defined _ISOC9X_SOURCE \
  214. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
  215. # define __USE_ISOC95 1
  216. #endif
  217. /* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2
  218. (and IEEE Std 1003.1b-1993 unless _XOPEN_SOURCE is defined). */
  219. #if ((!defined __STRICT_ANSI__ || (_XOPEN_SOURCE - 0) >= 500) && \
  220. !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
  221. # define _POSIX_SOURCE 1
  222. # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
  223. # define _POSIX_C_SOURCE 2
  224. # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
  225. # define _POSIX_C_SOURCE 199506L
  226. # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700
  227. # define _POSIX_C_SOURCE 200112L
  228. # else
  229. # define _POSIX_C_SOURCE 200809L
  230. # endif
  231. # define __USE_POSIX_IMPLICITLY 1
  232. #endif
  233. #if defined _POSIX_SOURCE || _POSIX_C_SOURCE >= 1 || defined _XOPEN_SOURCE
  234. # define __USE_POSIX 1
  235. #endif
  236. #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
  237. # define __USE_POSIX2 1
  238. #endif
  239. #if (_POSIX_C_SOURCE - 0) >= 199309L
  240. # define __USE_POSIX199309 1
  241. #endif
  242. #if (_POSIX_C_SOURCE - 0) >= 199506L
  243. # define __USE_POSIX199506 1
  244. #endif
  245. #if (_POSIX_C_SOURCE - 0) >= 200112L
  246. # define __USE_XOPEN2K 1
  247. # undef __USE_ISOC99
  248. # define __USE_ISOC99 1
  249. #endif
  250. #if (_POSIX_C_SOURCE - 0) >= 200809L
  251. # define __USE_XOPEN2K8 1
  252. # undef _ATFILE_SOURCE
  253. # define _ATFILE_SOURCE 1
  254. #endif
  255. #ifdef _XOPEN_SOURCE
  256. # define __USE_XOPEN 1
  257. # if (_XOPEN_SOURCE - 0) >= 500
  258. # define __USE_XOPEN_EXTENDED 1
  259. # define __USE_UNIX98 1
  260. # undef _LARGEFILE_SOURCE
  261. # define _LARGEFILE_SOURCE 1
  262. # if (_XOPEN_SOURCE - 0) >= 600
  263. # if (_XOPEN_SOURCE - 0) >= 700
  264. # define __USE_XOPEN2K8 1
  265. # endif
  266. # define __USE_XOPEN2K 1
  267. # undef __USE_ISOC99
  268. # define __USE_ISOC99 1
  269. # endif
  270. # else
  271. # ifdef _XOPEN_SOURCE_EXTENDED
  272. # define __USE_XOPEN_EXTENDED 1
  273. # endif
  274. # endif
  275. #endif
  276. #ifdef _LARGEFILE_SOURCE
  277. # define __USE_LARGEFILE 1
  278. #endif
  279. #ifdef _LARGEFILE64_SOURCE
  280. # define __USE_LARGEFILE64 1
  281. #endif
  282. #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
  283. # define __USE_FILE_OFFSET64 1
  284. #endif
  285. #if defined _BSD_SOURCE || defined _SVID_SOURCE
  286. # define __USE_MISC 1
  287. #endif
  288. #ifdef _BSD_SOURCE
  289. # define __USE_BSD 1
  290. #endif
  291. #ifdef _SVID_SOURCE
  292. # define __USE_SVID 1
  293. #endif
  294. #ifdef _ATFILE_SOURCE
  295. # define __USE_ATFILE 1
  296. #endif
  297. #ifdef _GNU_SOURCE
  298. # define __USE_GNU 1
  299. #endif
  300. #if defined _REENTRANT || defined _THREAD_SAFE
  301. # define __USE_REENTRANT 1
  302. #endif
  303. #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0 \
  304. && __GNUC_PREREQ (4, 1) && defined __OPTIMIZE__ && __OPTIMIZE__ > 0
  305. # if _FORTIFY_SOURCE > 1
  306. # define __USE_FORTIFY_LEVEL 2
  307. # else
  308. # define __USE_FORTIFY_LEVEL 1
  309. # endif
  310. #else
  311. # define __USE_FORTIFY_LEVEL 0
  312. #endif
  313. /* We do support the IEC 559 math functionality, real and complex. */
  314. #ifdef __UCLIBC_HAS_FLOATS__
  315. #define __STDC_IEC_559__ 1
  316. #define __STDC_IEC_559_COMPLEX__ 1
  317. #endif
  318. #ifdef __UCLIBC_HAS_WCHAR__
  319. /* wchar_t uses ISO 10646-1 (2nd ed., published 2000-09-15) / Unicode 3.1. */
  320. #define __STDC_ISO_10646__ 200009L
  321. #endif
  322. /* There is an unwholesomely huge amount of code out there that depends on the
  323. * presence of GNU libc header files. We have GNU libc header files. So here
  324. * we commit a horrible sin. At this point, we _lie_ and claim to be GNU libc
  325. * to make things like /usr/include/linux/socket.h and lots of apps work as
  326. * their developers intended. This is IMHO, pardonable, since these defines
  327. * are not really intended to check for the presence of a particular library,
  328. * but rather are used to define an _interface_. */
  329. #if !defined __FORCE_NOGLIBC && (!defined _LIBC || defined __FORCE_GLIBC)
  330. /* This macro indicates that the installed library is the GNU C Library.
  331. For historic reasons the value now is 6 and this will stay from now
  332. on. The use of this variable is deprecated. */
  333. /* uClibc WARNING: leave these aligned to the left, don't put a space after '#', else
  334. * broken apps could fail the check. */
  335. #undef __GNU_LIBRARY__
  336. #define __GNU_LIBRARY__ 6
  337. /* Major and minor version number of the GNU C library package. Use
  338. these macros to test for features in specific releases. */
  339. /* Don't do it, if you want to keep uClibc happy. */
  340. #define __GLIBC__ 2
  341. #define __GLIBC_MINOR__ 2
  342. #endif
  343. #define __GLIBC_PREREQ(maj, min) \
  344. ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
  345. #ifndef __UCLIBC__
  346. /* Decide whether a compiler supports the long long datatypes. */
  347. #if defined __GNUC__ \
  348. || (defined __PGI && defined __i386__ ) \
  349. || (defined __INTEL_COMPILER && (defined __i386__ || defined __ia64__)) \
  350. || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
  351. # define __GLIBC_HAVE_LONG_LONG 1
  352. #endif
  353. #endif
  354. /* This is here only because every header file already includes this one. */
  355. #ifndef __ASSEMBLER__
  356. # ifndef _SYS_CDEFS_H
  357. # include <sys/cdefs.h>
  358. # endif
  359. /* If we don't have __REDIRECT, prototypes will be missing if
  360. __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
  361. # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
  362. # define __USE_LARGEFILE 1
  363. # define __USE_LARGEFILE64 1
  364. # endif
  365. #endif /* !ASSEMBLER */
  366. /* Decide whether we can, and are willing to define extern inline
  367. * functions in headers, even if this results in a slightly bigger
  368. * code for user programs built against uclibc.
  369. * Enabled only in -O2 compiles, not -Os.
  370. * uclibc itself is usually built without __USE_EXTERN_INLINES,
  371. * remove "&& !defined __OPTIMIZE_SIZE__" part to do otherwise.
  372. */
  373. #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
  374. && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
  375. && (defined __extern_inline || defined __GNUC_GNU_INLINE__ || defined __GNUC_STDC_INLINE__)
  376. # define __USE_EXTERN_INLINES 1
  377. #endif
  378. #ifdef _LIBC
  379. # undef _FILE_OFFSET_BITS
  380. # undef __USE_FILE_OFFSET64
  381. # include <libc-internal.h>
  382. #endif
  383. #endif /* features.h */